package leetcode2;

public class Day2 {


    //96.交错字符串
    public boolean isInterleave(String s1, String s2, String s3) {
        int m=s1.length(),n=s2.length();
        if(m+n != s3.length()) return false;
        s1 = " " + s1;
        s2 = " " + s2;
        s3 = " " + s3;
        boolean[][] dp = new boolean[m+1][n+1];
        //1.初始化
        dp[0][0]=true;
        //初始化第一列,s2为空
        for(int i=1;i<=m;i++) {
            if(s1.charAt(i) == s3.charAt(i)) dp[i][0]=true;
            else break;
        }
        for(int i=1;i<=n;i++) {
            if(s2.charAt(i) == s3.charAt(i)) dp[0][i]=true;
            else break;
        }
        //2.
        for(int i=1;i<=m;i++) {
            for(int j=1;j<=n;j++) {
                dp[i][j] = (s1.charAt(i) == s3.charAt(i+j) && dp[i-1][j])
                        || (s2.charAt(j) == s3.charAt(i+j) && dp[i][j-1]);
            }
        }
        return dp[m][n];
    }
}
